Auxiliary system and method for accurate alignment of vehicle at lifting appliance end of quay crane
By installing a light source projection unit and a distance measurement and identification unit at the bottom of the quay crane spreader, combined with devices such as lidar, a clear parking space benchmark is provided, enabling precise positioning of the unmanned vehicle. This solves the problem of low positioning accuracy between the unmanned vehicle and the quay crane spreader, and improves operational efficiency and success rate.
Patent Information
- Application Number
- CN202610163996.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-05
- Publication Date
- 2026-05-05
AI Technical Summary
In existing technologies, the alignment accuracy and efficiency of unmanned vehicles and quay crane spreaders are low, making it difficult to achieve efficient and accurate container loading and unloading operations. In particular, alignment deviations are frequent in complex environments, leading to decreased loading and unloading efficiency and increased human intervention.
An end-corner light source projection unit, a center light source projection unit, and a distance measurement and recognition unit are installed at the bottom of the quay crane spreader. By projecting clear rectangular parking spaces and cross-shaped reference marks on the ground, and combining them with devices such as lidar to detect deviation information in real time, the unmanned vehicle is guided to park accurately.
It improved the alignment accuracy and efficiency of the unmanned vehicle and the quay crane spreader, reduced repeated parking adjustments and manual intervention, significantly improved operational efficiency, and ensured the successful parking of the unmanned vehicle on the first attempt.
Smart Images
Figure CN121979218A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of port equipment technology, specifically to a precise alignment assistance system and method for vehicles at the end of a quay crane spreader. Background Technology
[0002] With the widespread construction of automated container terminals, efficient and precise container loading and unloading docking of horizontal transport equipment under quay cranes has become a key link in improving operational efficiency. Currently, terminals generally use automated guided vehicles (AGVs) or intelligent guided vehicles (IGVs) to perform container handling tasks under quay cranes. In the existing operation process, IGVs typically enter the quay crane operation area according to the target parking position issued by the Container Terminal Positioning System (CPS) and wait for loading and unloading below the preset spreader placement position, such as hoisting containers from the IGV onto the corresponding ships.
[0003] However, in traditional quay crane alignment with unmanned vehicles such as AGVs or IGVs, the AGVs can only rely on their own navigation to get as close to the target point as possible within the positioning error range when parking. When there is a deviation between the actual position of the AGV and the quay crane, it can only be corrected in the following ways: the AGV repeatedly adjusts its parking position, moving forward, backward, or laterally multiple times; or the quay crane is remotely controlled by a human to make fine adjustments in height, forward, backward, left, and right to adapt to the final parking position of the vehicle. However, this method is inconvenient to operate, time-consuming, has low alignment accuracy, and is inefficient.
[0004] Furthermore, as the level of automation at ports continues to increase, some AGVs or IGVs utilize built-in LiDAR, depth-sensing cameras, and other identification devices to identify features such as the steel structure and guide channels of quay cranes, achieving a certain degree of "autonomous and precise vehicle-side alignment." However, in actual operations, due to the complex structure under the quay cranes, numerous obstructions, strong reflectivity of the steel structure, and scarce visual features, relying solely on the AGV's own identification devices for alignment still results in frequent lateral, longitudinal, and angular deviations. This makes it difficult to guarantee the alignment accuracy of the AGV, leading to decreased loading and unloading efficiency, increased waiting time for spreader equipment, and a higher rate of manual intervention. Summary of the Invention
[0005] The purpose of this application is to provide a precise alignment assistance system for vehicles at the end of a quay crane spreader, thereby improving the alignment accuracy and efficiency between the unmanned vehicle and the quay crane spreader.
[0006] To solve at least one of the above-mentioned technical problems, this application adopts the following technical solution:
[0007] According to a first aspect of this application, a precise vehicle alignment assistance system for a quay crane spreader is provided, comprising: an end-corner light source projection unit, a center light source projection unit, and a ranging and identification unit disposed at the bottom of the quay crane spreader; wherein, the end-corner light source projection unit is used to project four end-corner markers for unmanned vehicle identification on the ground, forming a rectangular parking space with the four end-corner markers as the four corners, and the center of the rectangular parking space corresponds to the center of the quay crane spreader; the center light source projection unit is used to project a cross-shaped reference marker for unmanned vehicle identification on the ground, and the center of the cross-shaped reference marker coincides with the center of the rectangular parking space; the ranging and identification unit is used to detect and acquire deviation information of the unmanned vehicle relative to the center reference of the quay crane spreader during the process of the unmanned vehicle approaching the end-corner markers and stopping, and to send the deviation information to the unmanned vehicle.
[0008] In one possible implementation of the first aspect above, the horizontal cross-section of the quay crane spreader is rectangular, and the corner light source projection unit includes four sets of point light source projection devices, which are correspondingly arranged at the four corners of the bottom of the quay crane spreader.
[0009] In one possible implementation of the first aspect described above, the point light source projection device is a laser point projector or a light-emitting diode dot matrix projector.
[0010] In one possible implementation of the first aspect described above, the central light source projection unit is located at the bottom center of the quay crane spreader, and the central light source projection unit is a light source cross projector.
[0011] In one possible implementation of the first aspect described above, the ranging and identification unit includes: multiple lidars disposed on the outer perimeter of the bottom of the quay crane spreader, for detecting the distance between the top surface of the unmanned vehicle and its surrounding edges relative to the quay crane spreader; and a signal processing module for receiving and processing the detection information from each lidar to obtain deviation information, and sending the obtained deviation information to the unmanned vehicle.
[0012] In one possible implementation of the first aspect described above, the lidar includes: a ranging module for detecting the distance between the top surface of the unmanned vehicle and the quay crane spreader; and an imaging module for scanning and identifying the four edges of the top surface of the unmanned vehicle to obtain the distance between the four edges of the top surface of the unmanned vehicle and the quay crane spreader.
[0013] In one possible implementation of the first aspect described above, the ranging and identification unit further includes a reflective identification component for identifying reflective identification strips set on the unmanned vehicle.
[0014] In one possible implementation of the first aspect described above, the deviation information includes lateral deviation information, longitudinal deviation information, and angular deviation information.
[0015] In one possible implementation of the first aspect described above, the ranging and identification unit is also used to transmit deviation information to the control system of the quay crane so that the control system of the quay crane can fine-tune the position of the quay crane spreader.
[0016] According to a second aspect of this application, a method for precise alignment assistance of a quay crane spreader end vehicle is provided, applied to the quay crane spreader end vehicle precise alignment assistance system of the first aspect described above. The method for precise alignment assistance of a quay crane spreader end vehicle of this application includes the following steps:
[0017] Adjust the quay crane spreader to a safe height;
[0018] The corner light source projection unit projects four corner markers of the rectangular parking space for unmanned vehicle identification onto the ground. The four corner markers form the four corners of the rectangular parking space. The center light source projection unit projects a cross-shaped reference marker for unmanned vehicle identification onto the ground. The center of the rectangular parking space corresponds to the center of the quay crane, and the center of the cross-shaped reference marker coincides with the center of the rectangular parking space.
[0019] When the unmanned vehicle enters the working area of the quay crane, the unmanned vehicle's identification device identifies the four corner markers and the cross-shaped reference marker to determine the parking boundary and parking center reference of the unmanned vehicle, and guides the unmanned vehicle to drive towards the center of the cross-shaped reference marker.
[0020] As the unmanned vehicle approaches and stops in the rectangular parking space, the ranging and identification unit at the bottom of the quay crane spreader detects and obtains the deviation information of the unmanned vehicle relative to the center reference of the quay crane spreader in real time, and sends the deviation information to the unmanned vehicle. The unmanned vehicle corrects the error based on the deviation information until it stops in the rectangular parking space.
[0021] The above-mentioned technical solution of this application has at least one of the following beneficial effects:
[0022] The precise positioning assistance system for vehicles at the quay crane spreader end according to this application includes an end-corner light source projection unit, a center light source projection unit, and a ranging and recognition unit installed at the bottom of the quay crane spreader. The end-corner light source projection unit projects four corner markers for the unmanned vehicle (UAV) to the ground, forming a rectangular parking space with these four corner markers as the four corners. The center light source projection unit projects a cross-shaped reference marker for the UAV to the ground, with the cross-shaped reference marker located at the center of the rectangular parking space. When the UAV enters the quay crane's operating area, its recognition device identifies the four corner markers and the cross-shaped reference marker, determining the UAV's parking boundary and parking center reference, guiding the UAV to quickly move towards the center of the cross-shaped reference marker. During the UAV's approach to the rectangular parking space and its subsequent parking, the ranging and recognition unit at the bottom of the quay crane spreader continuously detects and acquires the deviation information of the UAV relative to the quay crane spreader's center reference, and sends this deviation information to the UAV. The UAV then corrects the error based on the deviation information until it stops in the rectangular parking space. The cross-shaped reference markers also help determine whether there are still minor errors after the unmanned vehicle parks in the parking space, and thus determine whether the quay crane spreader needs to be fine-tuned.
[0023] Therefore, the precise vehicle alignment assistance system at the quay crane spreader end of this application, by providing a clear, stable, and visible spatial position benchmark at the spreader end to form the expected rectangular parking space, not only guides the unmanned vehicle (UAV) to quickly move towards the center of the expected rectangular parking space, but also detects the deviation information between the UAV and the pre-set parking space in advance. This allows the UAV to complete error correction before reaching the final parking position, thus enabling the UAV to achieve precise parking without relying on complex site environmental features. This improves the alignment accuracy and efficiency between the UAV and the quay crane spreader, significantly increasing the success rate of parking the UAV on the first attempt, reducing the frequency of repeated parking adjustments and manual remote control adjustments of the quay crane spreader, and improving overall operational efficiency. Furthermore, this application has a simple structure, is easy to install on the quay crane spreader, and has good engineering feasibility.
[0024] In addition, unless otherwise specified in the technical solution of this application, the technical solution can be implemented by conventional means in the field. Attached Figure Description
[0025] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0026] Figure 1This is a schematic diagram of a precise alignment auxiliary system for a quay crane spreader vehicle according to one embodiment of this application.
[0027] Figure 2 This is a structural schematic diagram of an unmanned vehicle, quay crane, and ship according to one embodiment of this application;
[0028] Figure 3 This is a flowchart illustrating a method for precise vehicle alignment assistance at the end of a quay crane spreader, according to one embodiment of this application.
[0029] Explanation of the labels in the attached drawings:
[0030] Corner light source projection unit 100; Corner mark 101;
[0031] Central light source projection unit 200; cross-shaped reference mark 201;
[0032] Ranging and recognition unit 300;
[0033] 400 gantry crane spreaders;
[0034] 500 driverless cars;
[0035] Ship 600. Detailed Implementation
[0036] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only some, not all, of the embodiments of this application, and are used merely to explain this application and are not intended to limit it. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0037] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "inner," "outer," "both ends," "both sides," "bottom," and "top," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the elements referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first," "second," "upper-level," "lower-level," "main," and "secondary," etc., are used for descriptive purposes only and can be simply used to more clearly distinguish different components, and should not be construed as indicating or implying relative importance.
[0038] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral molding; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0039] refer to Figure 1 , Figure 2 As shown, a schematic illustration of a precise alignment assistance system for a quay crane spreader vehicle according to an embodiment of this application is provided, which may include: an end corner light source projection unit 100, a center light source projection unit 200, and a distance measurement and identification unit 300.
[0040] The corner light source projection unit 100, the center light source projection unit 200, and the ranging and recognition unit 300 are located at the bottom of the quay crane spreader 400. The corner light source projection unit 100 projects four corner markers 101 for the unmanned vehicle 500 to be recognized on the ground, forming a rectangular parking space with the four corner markers 101 as the four corners. The center of the rectangular parking space corresponds to the center of the quay crane spreader 400. The center light source projection unit 200 projects a cross-shaped reference marker 201 for the unmanned vehicle 500 to be recognized on the ground. The center of the cross-shaped reference marker 201 coincides with the center of the rectangular parking space. The ranging and recognition unit 300 detects and acquires the deviation information of the unmanned vehicle 500 relative to the center reference of the quay crane spreader 400 during the process of the unmanned vehicle 500 approaching the corner markers 101 and parking, and sends the deviation information to the unmanned vehicle 500. It should be noted that the rectangular parking space refers to the virtual rectangular frame formed by the four corner markers 101.
[0041] After the unmanned vehicle 500 and the quay crane receive the work assignment, the unmanned vehicle 500 moves towards the quay crane's work area. Simultaneously, the corner light source projection unit 100 projects four corner markers 101 onto the ground for the unmanned vehicle 500 to identify the rectangular parking space. The four corner markers 101 form the rectangular parking space. The center light source projection unit 200 projects a cross-shaped reference marker 201 onto the ground for the unmanned vehicle 500 to identify, with the cross-shaped reference marker 201 located at the center of the rectangular parking space. When the unmanned vehicle 500 enters the quay crane's work area, its identification devices (such as radar and cameras) identify the four corner markers 101 and the cross-shaped reference marker 201, determining the parking boundary and parking center reference of the unmanned vehicle 500, and guiding the unmanned vehicle 500 to quickly move towards the center of the cross-shaped reference marker 201. As the unmanned vehicle 500 approaches and stops in the rectangular parking space, the ranging and identification unit 300 at the bottom of the quay crane spreader 400 detects and acquires the deviation information of the unmanned vehicle 500 relative to the center reference of the quay crane spreader 400 in real time, and sends the deviation information to the unmanned vehicle 500. The unmanned vehicle 500 corrects the error based on the deviation information until it stops in the rectangular parking space. The cross-shaped reference mark 201 also helps to determine whether there are still slight errors after the unmanned vehicle 500 stops in the parking space, and thus determine whether fine-tuning of the quay crane spreader 400 is needed. After the unmanned vehicle 500 and the quay crane spreader 400 are aligned, the quay crane lifts the container on the unmanned vehicle 500 onto the corresponding vessel 600.
[0042] Therefore, the precise vehicle alignment assistance system at the quay crane spreader end of this application, by providing a clear, stable, and visible spatial position reference at the spreader end to form the expected rectangular parking space, not only guides the unmanned vehicle 500 to quickly move towards the center of the expected rectangular parking space, but also detects the deviation information between the unmanned vehicle 500 and the pre-set parking space in advance. This allows the unmanned vehicle 500 to complete error correction before reaching the final parking position, thus enabling the unmanned vehicle 500 to achieve precise parking without relying on complex site environmental features. This improves the alignment accuracy and efficiency between the unmanned vehicle 500 and the quay crane spreader 400, significantly increasing the first-time parking success rate of the unmanned vehicle 500, reducing the frequency of repeated parking adjustments and manual remote control adjustments of the quay crane spreader 400, and improving overall operational efficiency. In addition, this application has a simple structure, is easy to install on the quay crane spreader 400, and has good engineering feasibility.
[0043] In some embodiments, reference Figure 1As shown, the horizontal cross-section of the quay crane spreader 400 is typically rectangular, and the four corner markers 101 correspond one-to-one with the locking holes at the four corners of the quay crane spreader 400. The corner light source projection unit 100 includes four sets of point light source projection devices, which are correspondingly located at the four corners of the bottom of the quay crane spreader 400. Each set of point light source projection devices may include one, two, or more point light source projection devices. The point light source projection devices are laser point projectors or light-emitting diode (LED) dot matrix projectors. This allows for clearer and more stable corner markers 101 to be formed on the ground, ensuring that the unmanned vehicle 500 can better detect and identify them to determine parking boundaries.
[0044] In some embodiments, reference Figure 1 As shown, the central light source projection unit 200 is located at the bottom center of the quay crane spreader 400. The central light source projection unit 200 is a cross-shaped light source projector. This allows for a clearer and more stable cross-shaped reference marker 201 to be formed at the center of the rectangular parking space, ensuring that the unmanned vehicle 500 can better detect and identify the parking center. It also facilitates determining whether there are still minor errors after the unmanned vehicle 500 parks in the parking space, thus determining whether fine-tuning of the quay crane spreader 400 is necessary, and improving the final alignment accuracy between the unmanned vehicle 500 and the quay crane spreader 400.
[0045] In some embodiments, reference Figure 1 As shown, the ranging and identification unit 300 may include multiple lidar sensors and a signal processing module. The multiple lidar sensors are positioned on the outer perimeter of the bottom of the quay crane spreader 400, and are used to detect the distance between the top surface and the surrounding edges of the unmanned vehicle 500 and the quay crane spreader 400. The signal processing module receives and processes the detection information from each lidar sensor to obtain deviation information, and then sends the obtained deviation information to the unmanned vehicle 500. The deviation information may include lateral deviation information, longitudinal deviation information, and angular deviation information.
[0046] As the unmanned vehicle 500 approaches and stops in the rectangular parking space, multiple LiDAR sensors continuously detect the distance between the top surface and the edges of the unmanned vehicle 500 and the quay crane spreader 400, and send the detection information to the signal processing module. The signal processing module processes the received detection information from each LiDAR sensor, compares it with pre-set parking position information, and calculates the lateral, longitudinal, and angular deviations of the unmanned vehicle 500 relative to the center reference of the quay crane spreader 400. This deviation information is then sent back to the unmanned vehicle 500, which performs lateral, longitudinal, and angular corrections based on the deviation information until it stops in the rectangular parking space. How the signal processing module calculates the deviation information of the unmanned vehicle 500 relative to the center reference of the quay crane spreader 400 can be achieved using existing calculation methods, and will not be described in detail here.
[0047] Optionally, refer to Figure 1 As shown, the lidar includes a ranging module and an imaging module. The ranging module is used to detect the distance between the top surface of the unmanned vehicle 500 and the quay crane 400, while the imaging module is used to scan and identify the four edges of the top surface of the unmanned vehicle 500 to obtain the distance between the four edges of the top surface of the unmanned vehicle 500 and the quay crane 400. This allows for more accurate detection of the distance between the top surface of the unmanned vehicle 500 and its four edges relative to the quay crane 400, and further, through the signal processing module, more accurate deviation information is obtained, improving the success rate of parking on the first attempt.
[0048] In some embodiments, the ranging and recognition unit 300 further includes a reflective recognition component for recognizing reflective recognition strips provided on the unmanned vehicle 500. The reflective recognition component can be a camera or the like. This allows for more accurate identification of the unmanned vehicle 500's position, further improving alignment accuracy.
[0049] In some embodiments, the ranging and identification unit 300 is further configured to transmit deviation information to the control system of the quay crane, so that the control system of the quay crane can fine-tune the position of the quay crane spreader 400. The quay crane control system fine-tunes the quay crane. After the unmanned vehicle 500 parks in the intended rectangular parking space, the ranging and identification unit 300 also sends the detected deviation information of the unmanned vehicle 500 relative to the center reference of the quay crane spreader 400 to the control system of the quay crane. The control system of the quay crane determines whether the unmanned vehicle 500 still has a slight deviation based on the deviation information. If the unmanned vehicle 500 still has a slight error, the control system of the quay crane controls the quay crane spreader 400 to adjust its position, such as controlling the quay crane spreader 400 to move up and down, forward and backward, or left and right in a fine-tuning manner for secondary precise alignment. Thus, through secondary fine-tuning, the alignment accuracy between the unmanned vehicle 500 and the quay crane spreader 400 is further improved.
[0050] According to an embodiment of this application, a method for precise alignment of a vehicle at the end of a quay crane spreader is also provided, which is applied to the precise alignment assistance system for the vehicle at the end of the quay crane spreader described above. (Reference) Figure 3 As shown, the precise positioning assistance method for the quay crane spreader end vehicle of this application may include the following steps:
[0051] Adjust the quay crane spreader to a safe height, for example, by using the quay crane's control system.
[0052] The corner light source projection unit projects four corner markers of the rectangular parking space for unmanned vehicle identification onto the ground. The four corner markers form the four corners of the rectangular parking space. The center light source projection unit projects a cross-shaped reference marker for unmanned vehicle identification onto the ground. The center of the rectangular parking space corresponds to the center of the quay crane, and the center of the cross-shaped reference marker coincides with the center of the rectangular parking space.
[0053] When the unmanned vehicle enters the working area of the quay crane, the unmanned vehicle's identification device identifies the four corner markers and the cross-shaped reference marker to determine the parking boundary and parking center reference of the unmanned vehicle, and guides the unmanned vehicle to drive towards the center of the cross-shaped reference marker.
[0054] As the unmanned vehicle approaches and stops in the rectangular parking space, the ranging and identification unit at the bottom of the quay crane spreader detects and acquires the deviation information of the unmanned vehicle relative to the center reference of the quay crane spreader in real time, such as lateral deviation information, longitudinal deviation information and angular deviation information, and sends the deviation information to the unmanned vehicle. The unmanned vehicle corrects the error based on the deviation information until it stops in the rectangular parking space.
[0055] In some embodiments, reference Figure 3 As shown, the precise positioning assistance method for the quay crane spreader end vehicle of this application may further include:
[0056] After the unmanned vehicle parks in a rectangular parking space, the ranging and recognition unit will send the deviation information of the unmanned vehicle relative to the center reference of the quay crane spreader to the quay crane control system. The quay crane control system will determine whether there is still a slight deviation of the unmanned vehicle based on the deviation information. If there is still a slight error of the unmanned vehicle, the quay crane control system will control the quay crane spreader to adjust its position, such as controlling the quay crane spreader to move up and down, forward and backward, or left and right in a fine manner to perform a second precise alignment.
[0057] Based on the various embodiments of this application described above, in the absence of explicit denial or conflict, the technical features of one embodiment may be advantageously combined with one or more other embodiments.
[0058] The above descriptions are merely some embodiments of this application, used only to illustrate the technical solutions of this application, and not to limit it. It should be understood that those skilled in the art can make improvements or substitutions based on the above descriptions without departing from the inventive concept of this application, and all such improvements and substitutions should fall within the protection scope of this application. In this case, all details can be replaced with equivalent elements, and materials, shapes, and sizes can also be arbitrary.
Claims
1. A precise vehicle positioning assistance system for a quay crane spreader end, characterized in that, include: An end-angle light source projection unit, a center light source projection unit, and a distance measurement and identification unit are installed at the bottom of the quay crane spreader; The corner light source projection unit is used to project four corner markers for unmanned vehicle identification on the ground, forming a rectangular parking space with the four corner markers as the four corners, and the center of the rectangular parking space corresponds to the center of the quay crane spreader. The central light source projection unit is used to project a cross-shaped reference mark for the identification of the unmanned vehicle onto the ground, and the center of the cross-shaped reference mark coincides with the center of the rectangular parking space; The ranging and recognition unit is used to detect and acquire deviation information of the unmanned vehicle relative to the center reference of the quay crane spreader during the process of the unmanned vehicle approaching the end corner mark and stopping, and to send the deviation information to the unmanned vehicle.
2. The precise positioning assistance system for the quay crane spreader end vehicle according to claim 1, characterized in that, The horizontal cross-section of the quay crane spreader is rectangular, and the corner light source projection unit includes four sets of point light source projection devices, which are correspondingly set at the four corners of the bottom of the quay crane spreader.
3. The precise positioning assistance system for the quay crane spreader end vehicle according to claim 2, characterized in that, The point light source projection device is a laser point projector or a light-emitting diode dot matrix projector.
4. The precise positioning assistance system for the quay crane spreader end vehicle according to claim 1, characterized in that, The central light source projection unit is located at the bottom center of the quay crane spreader, and the central light source projection unit is a light source cross projector.
5. The precise positioning assistance system for the quay crane spreader end vehicle according to claim 1, characterized in that, The ranging and identification unit includes: Multiple lidar sensors are installed around the bottom perimeter of the quay crane spreader to detect the distance between the top surface and the perimeter edges of the unmanned vehicle and the quay crane spreader. The signal processing module is used to receive and process the detection information from each of the lidars to obtain the deviation information, and then send the obtained deviation information to the unmanned vehicle.
6. The precise positioning assistance system for the quay crane spreader end vehicle according to claim 5, characterized in that, The lidar includes: A ranging module is used to detect the distance between the top surface of the unmanned vehicle and the quay crane spreader; An imaging module is used to scan and identify the four edges of the top surface of the unmanned vehicle to obtain the distance between the four edges of the top surface of the unmanned vehicle and the quay crane spreader.
7. The precise positioning assistance system for the quay crane spreader end vehicle according to claim 5, characterized in that, The ranging and identification unit also includes a reflective identification component, which is used to identify reflective identification strips set on the unmanned vehicle.
8. The precise positioning assistance system for the quay crane spreader end vehicle according to claim 1, characterized in that, The deviation information includes lateral deviation information, longitudinal deviation information, and angular deviation information.
9. The precise positioning assistance system for the quay crane spreader end vehicle according to claim 1, characterized in that, The ranging and identification unit is also used to transmit the deviation information to the control system of the quay crane, so that the control system of the quay crane can fine-tune the position of the quay crane spreader.
10. A method for precise alignment of a vehicle at the end of a quay crane spreader, characterized in that, The precise alignment assistance system for the quay crane spreader end vehicle as described in any one of claims 1 to 9 includes the following steps: Adjust the quay crane spreader to a safe height; The corner light source projection unit projects four corner markers of the rectangular parking space for unmanned vehicle identification onto the ground, forming a rectangular parking space with the four corner markers as the four corners. The center light source projection unit projects a cross-shaped reference marker for unmanned vehicle identification onto the ground. The center of the rectangular parking space corresponds to the center of the quay crane, and the center of the cross-shaped reference marker coincides with the center of the rectangular parking space. When the unmanned vehicle enters the working area of the quay crane, the unmanned vehicle's identification device identifies the four corner markers and the cross-shaped reference marker, determines the parking boundary and parking center reference of the unmanned vehicle, and guides the unmanned vehicle to drive towards the center of the cross-shaped reference marker. During the process of the unmanned vehicle approaching the rectangular parking space and parking, the ranging and recognition unit detects and obtains the deviation information of the unmanned vehicle relative to the center reference of the quay crane spreader in real time, and sends the deviation information to the unmanned vehicle. The unmanned vehicle performs error correction based on the deviation information until it stops in the rectangular parking space.